NL-23-0337, Response to Request for Additional Information Related to License Amendment Request to Revise the Frequency of Surveillance Requirement 3.6.3.5

Response to Request for Additional Information Related to License Amendment Request to Revise the Frequency of Surveillance Requirement 3.6.3.5

ML23125A226
Person / Time
Site:	Farley
Issue date:	05/05/2023
From:	Brown R Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NL-23-0337
Download: ML23125A226 (1)

Text

Regulatory Affairs 3535 Colonnade Parkway Birmingham AL 35243 205 992 5000 May 05, 2023 Docket Nos.: 50-348 NL-23-0337 50-364 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant - Units 1 and 2 Response to Request for Additional Information Related to License Amendment Request to Revise the Frequency of Surveillance Requirement 3.6.3.5 Ladies and Gentlemen:

By letter dated December 20, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22354A087), Southern Nuclear Operating Company (SNC) submitted a license amendment request (LAR) for the Joseph M. Farley Nuclear Plant (FNP)

Units 1 and 2. The LAR proposes to revise Surveillance Requirement (SR) 3.6.3.5 to eliminate event-based testing of containment purge valves with resilient seals and permit testing to be performed in accordance with the Surveillance Frequency Control Program.

By email dated April 5, 2023 (ML23095A083), the U.S. Nuclear Regulatory Commission (NRC) notified SNC that additional information is needed for the staff to perform their review.

The enclosure to this letter provides the SNC response to the NRC Request for Additional Information (RAI).

The conclusions of the No Significant Hazards Consideration and Environmental Consideration contained in the original application have been reviewed and are unaffected by this response.

In accordance with 10 CFR 50.91, a copy of this application, including attachments, is being provided to the designated Alabama Official.

This letter contains no regulatory commitments. If you have any questions, please contact Ryan Joyce at 205.992.6468.

U. S. Nuclear Regulatory Commission NL-23-0337 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 5th day of May 2023.

Respectfully submitted, R. Keith Brown Director, Regulatory Affairs Southern Nuclear Operating Company RKB/was/cbg

Enclosure:

SNC Response to Request for Additional Information cc: Regional Administrator, Region ll NRR Project Manager - Farley 1 & 2 Senior Resident Inspector - Farley 1 & 2 Alabama - State Health Officer for the Department of Public Health RType: CFA04.054

Joseph M. Farley Nuclear Plant - Units 1 and 2 Response to Request for Additional Information Related to License Amendment Request to Revise the Frequency of Surveillance Requirement 3.6.3.5 Enclosure SNC Response to Request for Additional Information

Enclosure to NL-23-0337 SNC Response to Request for Additional Information REQUEST FOR ADDITIONAL INFORMATION (RAI)

By letter dated December 20, 2022 (Agencywide Documents and Access Management System Accession No. ML22354A087), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Joseph M. Farley Nuclear Plant (Farley),

Units 1 and 2. The proposed LAR would revise the Farley, Units 1 and 2, Technical Specification (TS) 3.6.3, Containment Isolation Valves, Surveillance Requirement (SR) 3.6.3.5 to eliminate event-based testing of containment purge valves with resilient seals. The proposed LAR would eliminate And within 92 days of opening the valve from SR 3.6.3.5.

The Nuclear Regulatory Commission (NRC) staff reviewed the LAR and the NRC staff determined that more information is needed to complete its review.

Regulatory Analysis Basis In Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36, Technical specifications, the U.S. Nuclear Regulatory Commission (NRC) establishes its regulatory requirements related to the content of TSs. Pursuant to 10 CFR 50.36, TSs are required to include items in the following five specific categories: (1) safety limits, limiting safety system settings, and limiting control settings; (2) limiting conditions for operation (LCOs); (3) SRs; (4) design features; and (5) administrative controls. The regulation does not specify the particular requirements to be included in plants TSs.

The regulation 10 CFR part 50, Appendix J, Option B, Primary Reactor Containment Leakage Testing For Water-Cooled Power Reactors, Performance-Based Requirements, provides assurance that leakage through these containments or systems and components penetrating these containments does not exceed allowable leakage rates specified in the TS, and integrity of the containment structure is maintained during its service.

General Design Criteria 54, 55, 56, and 57 of Appendix A to 10 CFR Part 50 require, in part, that piping systems penetrating primary reactor containment be provided with isolation capabilities that reflect the importance to safety of isolating these piping systems.

Regulatory Guide (RG) 1.163, Performance-Based Containment Leak-Test Program (ML003740058), provides guidance on an acceptable performance-based leak-test program, leakage rate test methods, procedures, and analyses that may be used to comply with the performance-based Option B in Appendix J to 10 CFR Part 50.

Request for Additional Information EMIB-RAI-1 The LAR dated December 20, 2022, submitted by SNC, Section 3.4, Surveillance Frequency Control Program, second and third paragraph, state:

The proposed change will eliminate the event-based testing Frequency of within 92 days after opening a containment purge valve with resilient seals. The containment purge valves with resilient seals will be leak tested at a Frequency specified in the SFCP

[Surveillance Frequency Control Program] and any changes to the testing Frequency will be evaluated in accordance with the SFCP following the process in NEI [Nuclear Energy Institute] 04-10, Revision 1.

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Enclosure to NL-23-0337 SNC Response to Request for Additional Information FNP [Farley Nuclear Plant] TS 5.5.17, Containment Leakage Rate Testing Program, requires containment leakage rate testing to be in accordance with NEI 94-01, Industry Guideline for Implementing Performance-Based Option of 10 CFR [Title 10 of the Code of Federal Regulations] Part 50, Appendix J, Revision 3-A. NEI 94-01 requires the containment purge and vent valve testing Frequency to not exceed 30 months.

[Emphasis added.] Therefore, the testing Frequency established by the SFCP cannot exceed this length.

The updated Farley Technical Specification (TS) Section SR 3.6.3.5 states:

Perform leakage rate testing for containment penetrations containing containment purge valves with resilient seals.

Frequency: In accordance with the Surveillance Frequency Control Program (SFCP).

The NRC Safety Evaluation (SE) printed in NEI 94-01, Revision 3-A, Section 4.0, LIMITATIONS AND CONDITIONS (Reference 3 - ML12221A202) states:

The NRC staff finds that the guidance in NEI 94-01, Revision 3, is acceptable for referencing by licensees in the implementation for the optional performance-based requirements of Option B to 10 CFR Part 50, Appendix J. However, the NRC staff identified two conditions on the use of NEI 94-01, Revision 3.

As described above, LAR Section 3.4 and Farley TS 5.5.17 state that NEI 94-01 requires the containment purge and vent valve testing Frequency to not exceed 30 months. However, NEI 94-01, Revision 3-A (which is referenced in TS 5.5.17) allows valve testing beyond 30 months.

a. Please clarify and explain the discrepancy between the LAR Section 3.4 regarding the valve testing frequency not to exceed 30 months and TS 5.5.17 (and NEI 94-01, Revision 3-A) which allows extension of the valve testing frequency beyond 30 months.

b. Please explain the wording in Section 3.4, second paragraph, last sentence, which states Frequency will be evaluated in accordance with the SFCP following the process in NEI 04-10, Revision 1. However, TS 5.5.17 references NEI-94-01, Revision 3-A.

SNC Response

a. TS 5.5.17 documents the adoption of NEI 94-01, Revision 3-A, dated July 2012, and the conditions and limitations specified in NEI 94-01, Revision 2-A, dated October 2008 by FNP. NEI 94-01, Revision 3-A, and Revision 2-A discuss the performance factors that licensees must consider in determining test intervals. However, they do not address how to perform the tests because these details can be found in existing documents with reference provided to ANSI/ANS-56.8-2002.

ANSI/ANS-56.8-2002 Section 3.3.4.1, "Type B and Type C tests (excluding airlocks),"

states that "Containment purge and vent valves, boiling water reactor (BWR) main steam isolation valves, and BWR feedwater check valves shall not be put on extended test intervals. Extended test intervals are described as an interval of greater than 30 months.

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Enclosure to NL-23-0337 SNC Response to Request for Additional Information The corresponding statement in NEI 94-01 Section 10.2, "Type B and Type C Testing Frequencies," states that "If no plant-specific technical specifications are in effect for BWR and PWR containment purge and vent valves and/or BWR main steam and feedwater isolation valves, the interval for Type C tests should be limited to 30 months."

Even with the discussion of containment purge and vent valves in TS SR 3.6.3.5 the testing intervals for containment purge and vent valves shall not exceed 30 months as stated in RG 1.163, NEI 94-01 and ANSI/ANS 56.8-2002 as required by TS 5.5.17.

As discussed above, the programmatic requirement to limit the frequency of containment purge and vent valves to 30 months is in accordance with TS 5.5.17, Containment Leakage Rate Testing Program. LAR Section 3.4 regarding the valve testing frequency not to exceed 30 months does not represent a discrepancy with TS 5.5.17 (and NEI 94-01, Revision 3-A) which allows extension of the valve testing frequency beyond 30 months, however, limits containment purge and vent valves to 30 months.

b. NEI 94-01 Section 10.2, states in part for containment purge and vent valves, the interval for Type C tests should be limited to 30 months. This limitation in test frequency is the base interval for testing in accordance with NEI 94-01. NEI 94-01 and ANSI/ANS 56.8-2002 do not contain provisions for testing of Type C tested valves at a frequency of less than 30 months.

The SFCP has the capability to address testing intervals less than or equal to 30 months based on the leakage rate testing performance of the containment purge and vent valves. The response of the SFCP to excellent or poor/declining performance would be to perform an evaluation in accordance with the SFCP following the process in NEI 04-10, Revision 1, per TS 5.5.19.b.

EMIB-RAI-2 Farley, Units 1 and 2, Fifth 10-Year Interval Inservice Testing (IST) Program includes containment isolation valves (Reference 2 - ML19070A247). Please provide a response to the following:

a. Explain the impact of the deleted 92 days requirements on the Farley, Units 1 and 2, IST Program.

b. Containment Purge Valves are included in the Farley, Units 1 and 2, Fifth 10-Year IST Program (ML19070A247). Farley IST Program lists P13 - Containment Purge Valves Q1(2)P13V0281, Q1(2)P13V0282, Q1(2)P13V0283, Q1(2)P13V0284 in Section 10 Unit 1 Valve Table on pages 55 and 56, and Section 11 Unit 2 Valve Table on pages 55 and 56. Tables Frequency Colum list Frequency as LJ (Leak testing by Appendix J) and Plan Notes Column list STC see Note 3 (Abbreviation STC is Stroke Time Close).

Farley IST Program, Section 9, Valves Notes, Note No. 3 states that Any change in the frequency or components being tested by this surveillance will require reevaluation of Farley CR 558904 in accordance with Surveillance Frequency Control Program (SFCP).

Please explain and clarify the difference between leak testing frequencies of Containment Purge Valves as specified in Farley Fifth 10-Year IST Program versus SFCP as specified in the Farley TS.

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Enclosure to NL-23-0337 SNC Response to Request for Additional Information SNC Response

a. Containment isolation valves with a leakage rate testing requirement are tested by the IST Program in accordance with ASME Code for Operation and Maintenance of Nuclear Power Plants (OM) Code 2004 through the 2006 Addenda, Section ISTC-3620, Containment Isolation Valves, which states in part:

Containment isolation valves with a leakage rate requirement based on Appendix J program commitment shall be tested in accordance with the Owners 10 CFR 50, Appendix J program.

As shown above, ISTC-3620 does not contain any frequency requirements for testing.

The 92-day requirement currently in SR 3.6.3.5 is not part of an IST Program frequency requirement.

The IST Program specifies the performance of Type C Leakage Rate Testing (LJ-C) of the containment purge and vent valves at the IST Program leakage test frequency (LJ).

This requires the performance of leakage rate testing at the frequency specified in the Containment Leakage Rate Testing Program in accordance with 10 CFR 50 Appendix J, Option B. Therefore, there is no impact on the IST Program.

b. The assignment of Note No. 3 to the eight Containment Purge Valves for each unit is strictly associated with the performance of stroke time closed (STC) testing of the containment purge and vent valves using procedures FNP-1(2)-STP-18.3 and FNP-1(2)-

STP-18.5. The performance of STC testing is an IST Program requirement separate from the performance of LJ-C. STS testing of the air operated containment purge and vent valves is performed in accordance with ISTC-5131, Valve Stroke Testing, which states the following in part:

(a) Active valves shall have their stroke times measured when exercised in accordance with ISTC-3500.

SR 3.6.3.4 states the following regarding the STC testing of automatic power operated containment isolation valves:

Verify the isolation time of each automatic power operated containment isolation valve in the INSERVICE TESTING PROGRAM is within limits. Frequency - In accordance with the INSERVICE TESTING PROGRAM SR 3.6.3.6 states the following regarding actuation to the isolation position on an actual or simulated actuation signal:

Verify each automatic containment isolation valve that is not locked, sealed or otherwise secured in position, actuates to the isolation position on an actual or simulated actuation signal.

Frequency - In accordance with the Surveillance Frequency Control Program The TS Bases for SR 3.6.3.6 states the following:

Automatic containment isolation valves close on a containment isolation signal to prevent leakage of radioactive material from containment following a DBA. This E-4

Enclosure to NL-23-0337 SNC Response to Request for Additional Information SR ensures that each automatic containment isolation valve will actuate to its isolation position on a containment isolation signal (Phase A or Phase B). This surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

The review of Farley CR 558904 did not identify SR 3.6.3.5 as part of the scope of CR 558904. However, it did identify association with SR 3.6.3.6 as described above. The assignment of Note 3 is limited to SR 3.6.3.6 for the containment vent and purge valves as described above.

The IST Program specifies the performance of Type C Leakage Rate Testing (LJ-C) of the containment purge and vent valves at the IST Program leakage test frequency (LJ).

This requires the performance of leakage rate testing at the frequency specified in the Containment Leakage Rate Testing Program in accordance with 10 CFR 50 Appendix J, Option B.

EMIB-RAI-3 The current TS SR 3.6.3.5, Bases, states:

For containment purge valves with resilient seals, additional leakage rate testing beyond the test requirements of 10 CFR 50, Appendix J, Option B, is required to ensure OPERABILITY.

The containment purge and exhaust penetration leakage limit is based on not exceeding the total combined leakage rate limit for all Type B and C testing specified in 5.5.17, Containment Leakage Rate Testing Program. Operating experience has demonstrated that this type of seal has the potential to degrade in a shorter time period than do other seal types. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

Additionally, this SR must be performed within 92 days after opening the valve. The 92 day Frequency was chosen recognizing that cycling the valve could introduce additional seal degradation (beyond that occurring to a valve that has not been opened). Thus, decreasing the interval (from 184 days) is a prudent measure after a valve has been opened. [This paragraph is being deleted under the submitted LAR.]

First paragraph, third sentence, states that this type of seal has potential to degrade in a shorter time than do other seal types. By deleting SR requirements of 92 days, please explain the following:

a. How the valve resilient seal degradation will be measured.

b. Its impact on the degradation of the valves.

SNC Response

a. Containment Purge Valves Q1(2)P13V0281, Q1(2)P13V0282, Q1(2)P13V0283, and Q1(2)P13V0284 are 48-inch air operated butterfly valves with resilient seals. Each 48-inch containment purge valve is required to be verified sealed closed. SR 3.6.3.1 is designed to ensure that a gross breach of containment is not caused by an inadvertent E-5

Enclosure to NL-23-0337 SNC Response to Request for Additional Information or spurious opening of a containment purge valve. Detailed analysis of the purge valves failed to conclusively demonstrate their ability to close during a LOCA in time to limit offsite doses. Therefore, these valves are required to be in the sealed closed position during MODES 1, 2, 3, and 4.

Containment Purge Valves Q1(2)P13V0301, Q1(2)P13V0302, Q1(2)P13V0303, and Q1(2)P13V0304 are 8-inch air operated butterfly valves with resilient seals. These valves are operated as required during normal plant operations and for STC testing quarterly in accordance with the IST Program.

With the 48-inch valves sealed closed, the implementation of the 92-day frequency only addresses the cycling of the 8-inch valves and their potential for seal degradation. As stated in LAR section 2.3, the industry has made considerable improvement to the performance of containment purge and vent valves with resilient seals. Improved seal materials, quality control, and modifications of equipment and environmental conditions have corrected the valve deficiencies in many plants.

There is not a method to measure seal degradation. The performance of Type C leakage rate testing in accordance with TS 5.5.17 and SR 3.6.3.5 ensures that the seals are working properly, and the 8-inch valve disks are seated properly when closed during normal plant operation.

The seat leakage performance history of the FNP Containment Purge System resilient seal isolation valves has shown that cycling the 8-inch Q1(2)P13V0301, Q1(2)P13V0302, Q1(2)P13V0303, and Q1(2)P13V0304 valves has not introduced additional seal degradation (beyond that occurring to a valve that has not been opened).

Containment Purge Valves Q1(2)P13V0281, Q1(2)P13V0282, Q1(2)P13V0283, and Q1(2)P13V0284 are sealed closed in Modes 1, 2, 3 and 4.

Indications of excess valve degradation for the Containment Purge System resilient seal isolation valves is based on comparison of the leakage rate for each containment purge penetration to the previously measured leakage rate.

b. The performance history and the margin to the acceptance criteria for the Containment Purge System resilient seal isolation valves as documented in LAR Attachments 4 and 5, Unit 1(2) Quarterly Containment Purge Air System Containment Isolation Valve Leakage History, shows that the valves are not subject to substantial degradation over the operating cycle. The performance of leakage rate testing at the frequency stated as follows in RG 1.163 is adequate to monitor for degradation of the resilient seal isolation valves:

"Further, the interval for Type C tests for main steam and feedwater isolation valves in BWRs, and containment purge and vent valves in PWRs and BWRs, should be limited to 30 months as specified in Section 3.3.4 of ANSI/ANS-56.8-1994, with consideration given to operating experience and safety significance."

FNP operating experience supports the deletion of the SR requirement of 92 days.

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Enclosure to NL-23-0337 SNC Response to Request for Additional Information References

1. Southern Nuclear Operating Company (SNC) letter dated December 22, 2022, for License Amendment Request (LAR) to Revise Frequency of Technical Specification (TS) Surveillance Requirement (SR) 3.6.3.5 at Joseph M. Farley Nuclear (FNP) Plant - Units 1 and 2, to the U.S.

Nuclear Regulatory Commission (NRC) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22354A087).

2. Joseph M. Farley Nuclear Plant - Units 1 and 2 Inservice Testing Plan for Pumps and Valves, Fifth 10-Year Interval IST Program, dated March 11, 2019 (ADAMS Accession No. ML19070A247).

3. NEI 94-01, Revision 3-A, Nuclear Energy Institute - Industry Guidelines for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J, dated July 2012 (ADAMS Accession No. ML12221A202)

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